Incandescent-lamp socket



(No Model.)

P. G. ROCKWELL.

INGANDESOENT LAMP SOCKET.

No. 402,481. Patented Apr. 30, 1889.

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UNITED STATES PATENT OFFICE.

FREDERICK C. ROCIUVELL, OF HARTFORD, CONNECTICUT.

lNCANDESCENT-LAMP SOCKET.

SPECIFICATION forming part of Letters Patent No. 402,481, dated April 30, 1889.

Application filed January 24, 1889. Serial No. 297,453. (No model.)

To all whom may concern.-

Be it known that I, FREDERICK C. ROCK- WELL, of Hartford, Connecticut, have invented certain new and useful Improvements in Ineandescent-Lamp Sockets, of which the following is a specification.

My improvement relates to the socketpieces of incandescent electric lamps, and the object IS to provide a socketpiece that is cheap, light, firm, durable, that will not emit an offensive odor when heated, and that will render it impossible for the electricity to spark or shortcircuit through. the socket, whereby the mechanism in the socket may be simplified.

In the accompanying drawings, Figure l is a side view of a lamp with the socket-piece cut in central section. Fig. 2 is a side view of the socket-piece on enlarged scale. Fig. 3 is a sectional view of the latter.

In the drawings, the letter a denotes one form of an incandescent lamp, and b is the socket-piece thereof. Into this socket the circuit-wires lead and make connection with the leads of the filament, usually through the cutout mechanism 0. The socket-piece b is ordinarily made in two partsthe tubular shell I) and the cap b-but may be in one piece.

In the lamps now in use the metallic socketpieces have to be made comparatively large and the cut-out mechanism small and compact to keep it a su flicient distance from the walls of the socket to prevent shortcircuiting the C1'l1.l611t,2t11tl many forms of sockets require the insertion of rings of expensive insulatin g material to prevent contact between the socket-piece and the current-conducting parts. It has been found that even with these precautions when lamps are placed in damp places moisture will enter the socket through the wire-entrance and through the cut-outhandle opening and collect in the bottom be tween the conductors and the socket-walls and offer less resistance than the filament, consequently will short-circuit the current through the socket-piece.

'When the lamps are placed in shops where they are subject to considerable vibration, the parts work loose and spark with the socketpiece when they shake near enough to overcome the resistance of the atmosphere, which resistance in a shop is small on account of the amount of metallic dust floating in the atmos phere.

My improvement provides a simple and ethcient means for overcoming this sparking and 'short-circuiting,\vhicli is particularly incident with lamps lighted by alternating and hightension currents. To form the socket-piece b, a shell of thin paper, (Z, is rolled or pressed to the desired shape, forming a firm fibrous body of proper form, and this body is coated with a waterproofing and insulating material, (9, preferably by dipping the body in a solution of dissolved gum, as rubber or eopal, in which is mixed a hardening agent, as sulphur, and an earthy material, as alum or borax, giving the body an exterior surface of granular material. The body thus coated may be subj ected to heat and pressure to harden and solidify the coating, so the socket will retain its form. A shell thus made will prevent any leakage of the current, consequently reduces the danger of fire and shocks; will neither expand nor contract under changes of temperature, nor emit an olfensive odor when heated, as will the old socket-pieces; is thoroughly water-proof; can be formed rigid and firm; is cheaper than the old socket-pieces, and reduces the size of the sockets, in that the 0011- duoting parts can be secured to the walls of the socket without the intervention of special insulating-pieces.

I claim as my improvement 1. The herein-described shell for incandes cent electric-lamp sockets, formed of paper the surfaces of which are provided with a coating of insulating material of higher resistance than the paper, substantially as described, and for the purpose set forth.

2. The herein-described shell for incandescent electric-lamp sockets, formed from a sheet of paper the surfaces of which are provided with a coating of gum and an earthy material hardened by heat and pressure, whereby the shell is stiffened and rendered water-proof, fire-proof, an d insulating, substantially as described, and for the purpose set forth.

FREDERICK C. ROCKVELL.

lVitnesses:

HARRY R. WILLIAMS, A. F. LANGDON. 

